title: Preparation, characterization and pH-metric measurements of 4-hydroxysalicylidenechitosan Schiff-base complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Ru(III), Rh(III), Pd(II) and Au(III).
abstract: The 4-hydroxysalicylidenechitosan Schiff-base (2CS-Hdhba) was prepared by the condensation of 2,4-dihydroxybenzaldehyde with chitosan, and its metal complexes, [M(2CS-dhba)Cl(2)(H(2)O)(2)] (M(III)=Fe, Ru, Rh), [M'(2CS-dhba)(AcO)(H(2)O)(2)] (M'(II)=Co, Ni, Cu, Zn), [Pd(2CS-dhba)Cl(H(2)O)] and [Au(2CS-dhba)Cl(2)], are reported. These complexes were characterized by elemental analysis, by spectral data (FTIR, solid-phase (13)C NMR, UV-vis and ESR spectroscopy), by morphological observations (SEM and XRD), and by magnetic and thermal measurements. The Schiff base (2CS-Hdhba) behaves as a bidentate chelate with a single negative charge. The azomethine nitrogen and the deprotonated 2-hydroxy centres with the pendant glucosamine hydroxy functionality play no role in coordination. The dissociation constants of 2CS-Hdhba and the stability constants of some of its metal complexes have been determined pH-metrically.
authors.affiliation: Chemistry Department, Faculty of Science, Mansoura University 35516, Mansoura, Egypt.
authors.forename: Neveen A
authors.initials: NA
authors.lastname: Anan
authors.forename: Shawky M
authors.initials: SM
authors.lastname: Hassan
authors.forename: Eman M
authors.initials: EM
authors.lastname: Saad
authors.forename: Ian S
authors.initials: IS
authors.lastname: Butler
authors.forename: Sahar I
authors.initials: SI
authors.lastname: Mostafa
mesh_terms: D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D012545:Schiff Bases; D007854:Lead; D010165:Palladium; D006046:Gold; D003300:Copper; D012428:Ruthenium; D012238:Rhodium; D015032:Zinc